Lausanne, Switzerland - Vitamin-D deficiency may be an underlying factor in musculoskeletal pain and is a potentially treatable cause. This point is made by two groups of researchers in the recent literature [1,2] and echoes findings from US research [3] previously reported by rheumawire.
"Rheumatologists should screen patients of all origins with overall pain and/or risk factors for hypovitaminosis D3," says lead author Dr Gabrielle de Torrente de la Jara (Lausanne University, Switzerland). If vitamin-D deficiency is the diagnosis, treatment is beneficial and leads to a rapid resolution of symptoms, she adds. "Doctors should be aware of the importance of the disease and the impact of rapid diagnosis and treatment."
Writing in the July 17, 2005 issue of BMJ, Torrente de la Jara et al report 11 cases of symptomatic hypovitaminosis D3 in female asylum seekers [1]. These women presented after minimal exposure to sunlight and a history of bone pain, proximal muscle weakness, change in gait, or fatigue. They had had these symptoms for a mean duration of 38 months and were initially diagnosed as having possible somatization disorder (three patients), chronic back pain (four patients), or multiple unexplained somatic symptoms (three patients).
All the women had low levels of vitamin D, with a mean 25-hydroxycholecalciferol-serum level of 10.9 nmol/L. The researchers comment that although there is some dispute about the levels needed for health, anything below 20 nmol/L indicates severe deficiency, and concentrations of at least 75 nmol/L are necessary to maintain cellular function.
Treatment for most of the patients was two intramuscular injections of cholecalciferol (300 000 IU) at monthly intervals and an ongoing course of oral calcium (1000 mg) and cholecalciferol (20
"We already know that hypovitaminosis D3 provokes clinical symptoms and that immigrant women are at risk because of lifestyle, but our study shows that in 11 female asylum seekers, hypovitaminosis D3 is slow to be diagnosed and is associated with a potential misdiagnosis of somatization," de Torrente de la Jara tells rheumawire. "Therefore, before considering a somatization disorder, hypovitaminosis D3 should be considered in immigrant women with musculoskeletal symptoms." "Studies from Brussels and Boston have also shown that about 25% to 30% of asymptomatic adults have hypovitaminosis D3 at the end of the winter," says de Torrente. "The best test is 25-OH-vitamin D3 in the serum, but the timing is a bit tricky since the levels vary with the season. But if the patient has symptoms, the timing seems less relevant." Separately, another group of researchers—this time from the UK—reports in the August 2005 issue of the Annals of Rheumatic Diseases a high incidence of widespread pain in people of South Asian origin [2]. They also report that all the Asian women who had widespread pain had low levels of vitamin D, with levels of 25-hydrocholecalciferol below 10 ng/mL. Prompted by anecdotal reports from rheumatologists in the UK that patients with South Asian backgrounds are more likely to report widespread pain, Prof GJ Macfarlane (University of Manchester, UK) and colleagues carried out population-based cross-sectional surveys to determine whether this was indeed the case. When compared with 932 white Europeans, the 1945 South Asian subjects showed excess symptoms of widespread pain—12% vs 14%. After adjustments for age and sex, reducing the number of subjects to 137 South Asians and 121 white Europeans, pain among South Asians (9%) was higher than among Europeans (6%), a statistically significant difference (odds ratio 1.6, 95% CI 1.3-2.1). Macfarlane et al reviewed blood samples from 114 South Asians and 105 white Europeans and found that levels of serum 25-OH-vitamin D3 were significantly lower in the South Asians. Of the 114 South Asian subjects, 81 registered levels of 25-OH-vitamin D3 below 10 ng/mL, whereas only 10 of 105 Europeans showed the same low reading. "Owing to the small numbers, the relationship between vitamin D and widespread pain must be considered preliminary and requires further investigation," Macfarlane et al comment, but they add that "it may be one potentially treatable cause of widespread pain." Stronger words came from the US researchers who found widespread vitamin-D deficiency among patients presenting with pain in an article published in the December 2003 issue of the Mayo Clinic Proceedings [3], reported at the time by rheumawire. The authors, led by Dr Greg Plotnikoff (University of Minnesota, Minneapolis), found that 93% of all patients presenting with persistent nonspecific musculoskeletal pain were deficient in vitamin D, many severely so, and they concluded that all patients presenting with such symptoms should be screened for hypovitaminosis D.